Appendix C The study universe

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As already stated, this report presents both cross-sectional and longitudinal estimates. To conduct longitudinal analysis, it is necessary to work at the person level and not at the household level since the household universe is dynamic. Households form, change, and dissolve due to birth, marriage, divorce, death, and the comings and goings of household members, making it difficult to follow households over time. Therefore, household characteristics (including shelter costs, incomes, and STIRs) are attached to each SLID household member.

Analytical results are presented on a person basis by reporting on the numbers and percentages of people living in households with the various characteristics. To facilitate comparisons between longitudinal and cross-sectional estimates, most of the crosssectional analysis in Section 2 was also done at the person level.

Certain exclusions from the survey population are necessary. Table 19 shows how many people were excluded and the reason for exclusion. The first step, for longitudinal analysis only, was to eliminate those persons not present for all three survey years.

To make it easier to interpret results, people living in the following households were also excluded: (a) those with household incomes or shelter costs less than or equal to zero, (b) those where a household member operates a farm, and (c) those with more than one economic family, i.e., where at least one person in the dwelling was not related by blood, marriage or adoption. These three exclusions removed approximately 8% of the sample from cross-sectional analysis with the largest exclusion coming from the third criterion.

Positive incomes and shelter costs are essential to interpret the shelter cost-to-income ratio (STIR). Households can report negative incomes when, for instance, income from self-employment or investment includes losses that are larger than gains. Such households usually depend on alternative monetary sources such as loans, savings or capital gains. But these data are not collected in SLID, so it is not possible to assess how much money the household has to live on. Similarly, it is difficult to interpret the STIR if a household reports that it pays nothing for shelter when, for example, the use of a dwelling comes as part of employment compensation.

Farm operators are excluded because their shelter costs and farm operating costs may be so blended together that it is hard to obtain a reliable estimate of the actual shelter cost.

The exclusion of households with more than one economic family was done because the members of some of these households may make their housing decisions at the family or individual level and any household level estimate might be difficult to interpret¹. For example, in a roommate household, each of the roommates would have different incomes, although they might share the rent equally. A STIR calculated based on their total shelter costs and the sum of their incomes may not have the same meaning as a STIR calculated for a family or individual living alone.

Finally, the two models presented in Section 3 were run only on the adult (aged 16 and over) population, because certain questions such as Aboriginal status, immigration status and education level are not asked of those under age 16. See table 19 for a summary of the derivation of the universes.

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1. A household consists of all the people living in a dwelling, whereas an economic family consists only of those who are related by blood, marriage or adoption living together in a dwelling.